L-Arginine
CAS 74-79-3 C6H14N4O2
- CAS number
- 74-79-3
- EC number
- 200-811-1
- Formula
- C6H14N4O2
- Molar mass
- 174.20 g/mol
- Appearance
- White crystalline powder, odourless; water-soluble; basic.
L-Arginine is a basic amino acid carrying a guanidinium group that stays positively charged across the physiological pH range, and that single feature drives most of its industrial use. In biopharmaceutical processing it is the standard additive for suppressing protein aggregation during refolding and for cutting the viscosity of high-concentration antibody solutions, where it interacts with charged patches on the protein surface and keeps molecules from associating. It is also the metabolic precursor to nitric oxide, which is what put it into sports nutrition and clinical infusion. Ehlinar supplies food, feed and pharmacopoeial grades.
Applications
Grades & packaging
Food (FCC), pharmaceutical (USP/EP/JP/ChP), feed and reagent grades, with assay around 98.5–101.5%; the free base and the hydrochloride salt are distinct products.
- 25 kg kraft bags/fiber drums with PE liner
- Pharma: double-PE in drum
How we supply
- Certificate of Analysis (CoA), lot-specific where available
- Safety Data Sheet (SDS / MSDS)
- Technical Data Sheet (TDS)
- Certificate of Origin / Certificate of Conformity
Independent third-party inspection can be arranged on request, with the agency and scope agreed per trade. Representative samples can be requested for qualification, subject to supplier availability. We recommend incoming quality control against the agreed CoA.
Quoted on standard Incoterms (e.g. EXW, FOB, CIF, DAP) as agreed per trade. Delivery region, packaging and grade are confirmed per quote.
Documents and services above are subject to supplier availability and confirmed per quote; nothing here is an offer.
Typical / indicative values — not a binding specification
| Property | Typical |
|---|---|
| Assay | ~98.5–101.5% |
| Water solubility | Soluble |
| Solution character | Basic |
Also known as
L-Arg · (S)-2-amino-5-guanidinopentanoic acid · L-(+)-arginine
Frequently asked questions
- Free base or hydrochloride?
- They are different products with different CAS numbers (free base 74-79-3; HCl salt 1119-34-2).
- Which grade for a drug or injectable?
- USP/EP/JP grade for pharma and parenteral use; FCC for supplements and food.
- How is it stored?
- Cool, dry and closed; protect from CO₂ and moisture.
- Why is arginine added to antibody formulations?
- To keep concentrated protein solutions workable. Arginine suppresses protein-protein association, which limits aggregation and reduces viscosity. Published work on monoclonal antibody solutions at around 250 mg/mL reports viscosity falling several-fold when arginine salts are added. The precise mechanism is still debated; the effect is well documented.
- Does an arginine solution need pH adjustment?
- Usually. L-Arginine free base is strongly basic and gives an alkaline solution, so formulations commonly pair it with an acid — hydrochloric acid, or glutamic acid in the arginine-glutamate combinations used to cut viscosity — to land on the target pH.
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Related products
Figures and identifiers here are compiled from public references and provided for general information; they are indicative, not a specification. See all products.